Currently, national and international studies on substitutes for vitreous body are numerous, mainly including inert gas, silicone oil, heavy silicone oil, perfluorocarbon liquids, and hydrogels composed of high molecular weight hydrophilic polymers being the national or international research focus in the 1990s. However, their therapy results are not satisfying, some of which could result in serious complications, for example, inert gas for instance C3F8 may cause cataract easily and lose the effect of tamponade at about two weeks after the surgery such that it could not generate sustained top-pressure on the retina; Perfluorocarbon liquids is toxic to the retina such that it could not settle in the cavity of vitreous body for a long time and could be utilized in surgery only. Additionally, perfluorocarbon liquids is easy to remain in the eyes and difficult to remove after reaction with water. Present substitutes for silicon oils widely used in clinic could result in glaucoma and cataract and will self-emulsify within a particular time. The emulsified substitutes had to be removed. However, upon removing, the retina is easy to detach again. Repetitive surgeries not only aggravated the burden of patients but also seriously impaired the vision of the patients; Even though the surgery is successful, the vision of the patients is very poor resulting from that low refractive index of silicon oil could not generate adequate top pressure on the breaks underlying the retina, and that the diopter in eyeball shifted to high hyperopia after filling; Additionally, after surgeries, patients had to lie on stomach for a long time to prevent silicon oil from flowing into the anterior chamber, thus making the patients very agonized. Hydrogels mainly included PVP hydrgels, PVA hydrogels, PAM hydrogels and Poly (1-vinyl-2-pyrrolidone) hydrogels, and so on. However, these hydrogels are still at the experimental stage in ophthalmology, and so far no one of these hydrogels is performed in clinic application resulting in lack of observation on the long-term therapeutic effect on the toxicity to the eyes and the price is very high. The patients could not afford it. Finding out vitreous substitutes which met physiological needs and are more economical is required, which is one of problems disturbing the doctors for vitreous retinal disorders in the century.
How to make an artificial vitreous body of which both structure and function are the same as those of the natural vitreous body is one of the keys to ensure the success of vitrectomy. Up to now, the components of vitreous body are not fully known. Based on the conditions of modern science and technology, the need to make an artificial vitreous body of which both structure and function are perfect is impractical. The current substitutes for vitreous body are sometimes called as artificial vitreous body. Implantation methods are performed by directly injecting the substitutes for vitreous body into the cavity of vitreous body to support the retina to prevent the retina from detaching again.
Therefore, without pursuing to make a fully physiological artificial vitreous body, the research thinking is changed to restore the most important function of vitreous body, i.e. support of retina so as to avoid repetitive retinal detachment, which is also a method to resolve the problem. Here we design a novel therapy method as using foldable capsular vitreous body (FCVB) to substitute the natural vitreous body. The FCVB consist of a thin capsule, drainage tube and valve. And it also equipped with auxiliary tools: the ejector handle. Chinese Patent No. ZL 03126845.5 discloses a technical scheme and manufacture method for FCVB. Chinese Patent Publication No. CN1810301 (A) and US Patent Publication No. US2007173933 (A1) further limit the material and manufacturing process (dip-molding) of FCVB. The present patent application further extends the material and another manufacturing process of FCVB. New mould design method and capsule pressure regulating drainage valve are added.